Adjustable chocks are known in the art. See, for example, U.S. Pat. No. 7,438,274, issued to René Vermeulen for “Adjustable foot for setting up equipment in alignment” and incorporated herein by reference, and U.S. Pat. No. 6,068,234 (corresponds to WO97/35144), issued to Elbert Keus for “Setting foot provided with sealing means”, and incorporated herein by reference.
Each of the adjustable chock of U.S. Pat. No. 7,438,274 and the adjustable chock of U.S. Pat. No. 6,068,234 is referred to herein below as the known adjustable chock. The known adjustable chock comprises a first element, an intermediate element and a second element.
The first element has a rotationally symmetrical first surface that is convex. The first element has a first through-hole extending across the first element. The first through-hole is arranged coaxially with a first axis of rotational symmetry of the first surface.
The intermediate element has a rotationally symmetrical intermediate surface that is concave. The intermediate element has an intermediate through-hole extending across the intermediate element. The intermediate through-hole is arranged coaxially with the rotationally symmetrical intermediate surface. The intermediate surface and the first surface are shaped complementarily and engage in operational use of the known adjustable chock. As a result, an orientation of the first axis of rotational symmetry of the first surface and an orientation of an intermediate axis of rotational symmetry of the intermediate surface can be adjusted relative to one another by sliding the first element across the intermediate element. Underneath the intermediate surface, the intermediate element has a hollow shaft that is arranged coaxially with the rotationally symmetrical intermediate surface. The intermediate through-hole of the intermediate element is arranged coaxially with the hollow-shaft. The hollow shaft has an external screw thread. The hollow shaft is configured for accommodating a shank of a bolt.
The second element has a second through-hole with an internal screw thread that matches the external screw thread of the hollow shaft.
In operational use of the known adjustable chock, a top surface of the first element abuts a piece of machinery, and a bottom surface of the second element abuts a support. The height of the known chocks is adjustable by means of rotating the intermediate element relative to the second element. The pitch of the external screw thread (and of the matching internal screw thread) determines the change in height per unit of angle of rotation. The minimum height is reached when the hollow shaft has been screwed so far into the second element that the hollow shaft abuts the support. The maximum change in height attainable depends on, among other things, an axial distance over which the hollow shaft can travel relative to the second element while the external screw thread and the internal screw thread remain engaged.